Abstract: A connection establishment method includes a terminal device obtaining historical data of a multipath transmission control protocol (MPTCP) connection established between the terminal device and an application server. The historical data includes a data transmission delay of a transmission control protocol (TCP) connection corresponding to a Wi-Fi network and a data transmission delay of a TCP connection corresponding to a cellular network. The terminal device determines, based on the historical data, that the data transmission delay of the TCP connection corresponding to the cellular network is less than or equal to the data transmission delay of the TCP connection corresponding to the Wi-Fi network, and establishes a first TCP connection to the application server through an interface of the cellular network; and after the first TCP connection is successfully established, the terminal device establishes a second TCP connection to the application server through an interface of the Wi-Fi network.

Abstract: A network switching method includes transmitting, by an electronic device, data using a wireless local area network, when a data transmission delay of the wireless local area network is greater than a first threshold, switching, by the electronic device, to transmitting data using both the wireless local area network and a mobile network, and when the electronic device transmits data using both the wireless local area network and the mobile network, if the data transmission delay of the wireless local area network is greater than a second threshold, switching, by the electronic device, to transmitting data using the mobile network, where the first threshold is less than the second threshold.

Abstract: A round-trip time (RTT) evaluation system includes sending, by a first device, a plurality of packets to a second device on a path, where each of the packets carries a timestamp indicating a sending time of a corresponding packet, determining, by the second device based on a statistical value of one-way delays (OWDs) of the packets, timestamps carried in the packets, sending, by the second device, an acknowledgements (ACKs) to the first device, where the ACKs include the timestamps and ACK time information, and determining, by the first device, measurement values of an RTT of the path based on the timestamps, the ACK time information, and times when the ACKs are received.

Abstract: A network switching method includes transmitting, by an electronic device, data using a wireless local area network, when a data transmission delay of the wireless local area network is greater than a first threshold, switching, by the electronic device, to transmitting data using both the wireless local area network and a mobile network, and when the electronic device transmits data using both the wireless local area network and the mobile network, if the data transmission delay of the wireless local area network is greater than a second threshold, switching, by the electronic device, to transmitting data using the mobile network, where the first threshold is less than the second threshold.

Abstract: This application describes transmission control methods and devices. One method comprises: sending, by a first device to a second device, first control signaling that instructs the second communications device to send a first group of data packets, the first control signaling comprises a first packet sequence number, a first packet sequence number range, and a first transmission time interval, the first group of data packets correspond to sequence numbers within the first packet sequence number range starting from the first packet sequence number, and the first transmission time interval indicates a time interval for sending data packets of the first group of data packets; and receiving, by the first device from the second device, at least one data packet in the first group of data packets.

Abstract: A network switching method includes transmitting, by an electronic device, data using a wireless local area network, when a data transmission delay of the wireless local area network is greater than a first threshold, switching, by the electronic device, to transmitting data using both the wireless local area network and a mobile network, and when the electronic device transmits data using both the wireless local area network and the mobile network, if the data transmission delay of the wireless local area network is greater than a second threshold, switching, by the electronic device, to transmitting data using the mobile network, where the first threshold is less than the second threshold.

Abstract: This application provides a data transmission method and an electronic device. The method includes: establishing, by an electronic device, a multipath transmission control protocol MPTCP connection to a first application server, where the MPTCP connection includes a first TCP connection and a second TCP connection, and a data transmission delay of the first TCP connection is less than a data transmission delay of the second TCP connection; and receiving, by the electronic device, indication information from the first application server, where the indication information includes a type identifier used to indicate a type of a data stream sent by the first application server; receiving, by the electronic device preferentially by using the first TCP connection or the second TCP connection, the data stream from the first application server according to the indication information.

Abstract: A connection establishment method includes a terminal device obtaining historical data of a multipath transmission control protocol (MPTCP) connection established between the terminal device and an application server. The historical data includes a data transmission delay of a transmission control protocol (TCP) connection corresponding to a Wi-Fi network and a data transmission delay of a TCP connection corresponding to a cellular network. The terminal device determines, based on the historical data, that the data transmission delay of the TCP connection corresponding to the cellular network is less than or equal to the data transmission delay of the TCP connection corresponding to the Wi-Fi network, and establishes a first TCP connection to the application server through an interface of the cellular network; and after the first TCP connection is successfully established, the terminal device establishes a second TCP connection to the application server through an interface of the Wi-Fi network.

Abstract: Based on this application, one or more parameters for a multipath connection in a redundant transmission mode that are used to represent path characteristics are measured in the redundant transmission mode, and the one or more parameters are compared with a parameter that is measured in a multipath transmission mode and that is used to represent a path characteristic of an aggregated path of the connection at this time.

Abstract: This application discloses a connection establishment method implemented in an end node of the connection. The method includes: obtaining transmission status information of at least two available paths, the transmission status information of each available path of the at least two available paths indicates transmission performance of the each available path, the at least two available paths corresponding to different types of networks; determining a better available path with better transmission performance, the better available path determined based on the transmission status information of the at least two available paths; and establishing the connection using a network corresponding to the better available path.

Abstract: This application provides a data transmission method and an electronic device. The method includes: establishing, by an electronic device, a multipath transmission control protocol MPTCP connection to a first application server, where the MPTCP connection includes a first TCP connection and a second TCP connection, and a data transmission delay of the first TCP connection is less than a data transmission delay of the second TCP connection; and receiving, by the electronic device, indication information from the first application server, where the indication information includes a type identifier used to indicate a type of a data stream sent by the first application server; receiving, by the electronic device preferentially by using the first TCP connection or the second TCP connection, the data stream from the first application server according to the indication information.

Abstract: A link detection technology. In a link detection method, when a target event occurs on paths, in a plurality of paths, whose quantity exceeds a preset quantity, whether the paths on which the target event occurs share a bottleneck link is detected, and congestion control is performed. It can be learned that in the technical solution provided in the embodiments of this application, the target event is a trigger, and shared bottleneck detection is performed after the quantity of the paths on which the target event occurs exceeds the preset quantity. This implements purposeful link detection, reduces system overheads, and brings a fast convergence speed.

Abstract: A round-trip time (RTT) evaluation system includes sending, by a first device, a plurality of packets to a second device on a path, where each of the packets carries a timestamp indicating a sending time of a corresponding packet, determining, by the second device based on a statistical value of one-way delays (OWDs) of the packets, timestamps carried in the packets, sending, by the second device, an acknowledgements (ACKs) to the first device, where the ACKs include the timestamps and ACK time information, and determining, by the first device, measurement values of an RTT of the path based on the timestamps, the ACK time information, and times when the ACKs are received.

Abstract: This application describes transmission control methods and devices. One method comprises: sending, by a first device to a second device, first control signaling that instructs the second communications device to send a first group of data packets, the first control signaling comprises a first packet sequence number, a first packet sequence number range, and a first transmission time interval, the first group of data packets correspond to sequence numbers within the first packet sequence number range starting from the first packet sequence number, and the first transmission time interval indicates a time interval for sending data packets of the first group of data packets; and receiving, by the first device from the second device, at least one data packet in the first group of data packets.

Abstract: Based on this application, one or more parameters for a multipath connection in a redundant transmission mode that are used to represent path characteristics are measured in the redundant transmission mode, and the one or more parameters are compared with a parameter that is measured in a multipath transmission mode and that is used to represent a path characteristic of an aggregated path of the connection at this time.

Abstract: A link detection technology. In a link detection method, when a target event occurs on paths, in a plurality of paths, whose quantity exceeds a preset quantity, whether the paths on which the target event occurs share a bottleneck link is detected, and congestion control is performed. It can be learned that in the technical solution provided in the embodiments of this application, the target event is a trigger, and shared bottleneck detection is performed after the quantity of the paths on which the target event occurs exceeds the preset quantity. This implements purposeful link detection, reduces system overheads, and brings a fast convergence speed.

Abstract: A network switching method includes transmitting, by an electronic device, data using a wireless local area network, when a data transmission delay of the wireless local area network is greater than a first threshold, switching, by the electronic device, to transmitting data using both the wireless local area network and a mobile network, and when the electronic device transmits data using both the wireless local area network and the mobile network, if the data transmission delay of the wireless local area network is greater than a second threshold, switching, by the electronic device, to transmitting data using the mobile network, where the first threshold is less than the second threshold.

Abstract: A data transmission method and apparatus, where a transmission end determines a redundancy time according to a delay requirement of a service, where the redundancy time indicates a time used for transmitting redundant data of native data of the service, and the redundancy time is less than or equal to a time indicated by the delay requirement. The transmission end determines a redundancy quantity N. The transmission end determines N redundancy transmission time intervals according to the redundancy time and the redundancy quantity. After the native data of the service is sent, in case of feedback data is not received within an nth redundancy transmission time interval, transmitting the redundant data of the native data for the nth time according to the nth redundancy transmission time interval.

Abstract: A data transmission method and apparatus, where a transmission end determines a redundancy time according to a delay requirement of a service, where the redundancy time indicates a time used for transmitting redundant data of native data of the service, and the redundancy time is less than or equal to a time indicated by the delay requirement. The transmission end determines a redundancy quantity N. The transmission end determines N redundancy transmission time intervals according to the redundancy time and the redundancy quantity. After the native data of the service is sent, in case of feedback data is not received within an nth redundancy transmission time interval, transmitting the redundant data of the native data for the nth time according to the nth redundancy transmission time interval.

Abstract: The present invention provides a data transmission method. In the method, according to a pre-obtained network status variable and a pre-obtained transmission success rate, a transmit end obtains a quantity of redundant data packets that need to be transmitted for a data packet. The transmit end also obtains a redundant data packet scheduling method according to the quantity of redundant data packets. Then the transmit end send a redundant data packet according to the redundant data packet scheduling method.